Technical Strange suspension lower arm problem

[vexorg]

My daughter has had this car for a year, it's a 2015 1.2 Fiat 500, 36k miles. She brought it over as it needed an MOT and service and the limit of her looking after a car is putting in petrol (because she has to).

I done the service on it, very nice work by fiat on the UK version for the pollen/cabin filter, that alone took longer that the rest of the service.

Anyway, she had said there was a noise coming from the car, and driving it to the MOT centre there were some pretty loud and bad sounding knocking noises over every bump. I was thinking at least they'd say what part was worn as part of the MOT, but oddly it passed.

Given the low mielage, I thought it could only be the arb drop links, UK roads are bad for potholes. Changed them, but the old ones didn't seem that bad.

I drove the car back to my daughter, and although better, there was still some heavy knocks on bigger road bumps.

I had a look under the car when I got there and the rear of the lower arms were sitting funny, the metal of the arm was right down on the subframe. See here for where I mean:

I had limited tools not being at home, so got a screwdriver and levered the arm up, and it moved, some pictures as I was stuggling to see it right at the side of the road:

Both sides were exactly the same. These look like original arms, as were the ARB links. The rubber seems to be intact, just that the metal arm has moved down. I've levered them up as best I can with what I had, but looks like they will need replaced.

I wouldn't expect issue on those bushes for 80k / 100k miles or 10 years typically on other cars. Is this a common problem on fiat 500s?
I've not come across this issue searching on google.

 

[jrkitching]

Is this a common problem on fiat 500s?

Yes. Some have failed after as little as 20k. On those models fitted with larger/wider wheels, they tend not to last as long.

Changing the lower arms complete is the obvious solution; various brands are available from all the usual sources, at various prices. OEM replacements will likely only last as long as the originals. If you want them to be more durable, buy something decent such as Lemforder.

You'll need to remove the front bumper to change the arms. This is much easier with a second person to help; also beware of rusted fastenings.

very nice work by fiat on the UK version

It's not just the pollen filter, the whole clutch actuating mechanism on RHD cars is dubious, to say the least, and another common source of problems.

 

[vexorg]

Thanks, yeah, it has the bigger grey sporty looking alloy wheels.
I'm more amazed it passed the MOT.

Looks like a haynes manual will be needed, save some time looking for all the fixings that hold the bumper on.

My usual motorfactors has changed to Napa for the suspension parts.

I hate ECP, overpriced and have supplied me the wrong parts a few times. They dont list lemforder either.

Do you know if the arms are the same across the range for the 500?

Or is there a variation depending on model or year?

 

[jimboy]

I would agree with Lemforder parts, they are regarded highly in the DIY spanner fraternity

 

[Pickwick]

Looks like a haynes manual will be needed, save some time looking for all the fixings that hold the bumper on.

You might find eLEARN helpful for this too.

There's an online version here -

http://4cardata.info/elearn/312/2

in which replacing the lower arm is described here -

http://4cardata.info/elearn/312/2/312000000/312000000/312000005/312001956

There's also a copy of the above in the Forum's Download Library here.

 

[vexorg]

Thanks, that's quite useful, though not sure I can set the height to the recommended micrometre before tightening the bolts. Setting it to 187.485mm made me smile.

 

[jrkitching]

Just leave the final tightening until the weight of the car is on its wheels and you'll be fine.

 

[vexorg]

Just leave the final tightening until the weight of the car is on its wheels and you'll be fine.

Just having a look at more detail now, you cant access that front arm bolt unless you drop the car back on the ground with the front pieces of the subframe are still off (the third load line part).
Is that the normal method of setting the position, then jack it back up to put it all back together again?

 

[John202020]

Just having a look at more detail now, you cant access that front arm bolt unless you drop the car back on the ground with the front pieces of the subframe are still off (the third load line part).
Is that the normal method of setting the position, then jack it back up to put it all back together again?

Have to say when I replaced ours I just tightened everything up on the axle stands, never had an issue.

 

[vexorg]

Have to say when I replaced ours I just tightened everything up on the axle stands, never had an issue.

I've read about this on other cars too, the issue is that the rubber on the bush is supposed to be relaxed when the car is sitting normally, and then will be under tension as the arm moves up or down. However, if you tighten it at the fully down position, then it's under tension in the normal position, and even more tension when it's forced upwards.

 

[vexorg]

A fun day yesterday of finding all the bolts and nuts to get into the lower arms. It's not that bad a job, though dont think the screws on the wheel liner will last another few years without being blobs of rust. I could probably do it in half the time next time since I know how it goes together now.

Bushes just fell out when they were removed!

Afterwards I took it for wheel alignment, and there was still a noise, more of a vibrating noise of the exhaust or engine part touching the body. Turned out to be this bolt loose that hold the air pipe on the front slam panel. Just seemed to resonate with the engine vibration.

 

[chris3234]

:worship:

A fun day yesterday of finding all the bolts and nuts to get into the lower arms. It's not that bad a job, though dont think the screws on the wheel liner will last another few years without being blobs of rust. I could probably do it in half the time next time since I know how it goes together now.

Bushes just fell out when they were removed!

Afterwards I took it for wheel alignment, and there was still a noise, more of a vibrating noise of the exhaust or engine part touching the body. Turned out to be this bolt loose that hold the air pipe on the front slam panel. Just seemed to resonate with the engine vibration.

I had that issue with my 1.3 diesel 500 came of the motorway and was thinking what the hells wrong with the car as that was rattling a lot

 

[greypanda]

Both sides were exactly the same. These look like original arms, as were the ARB links. The rubber seems to be intact, just that the metal arm has moved down. I've levered them up as best I can with what I had, but looks like they will need replaced.

I wouldn't expect issue on those bushes for 80k / 100k miles or 10 years typically on other cars. Is this a common problem on fiat 500s?
I've not come across this issue searching on google.

Yes my 2016 Fiat 500 had them replaced at 18k miles. Had knocking coming from the front, thought it was the drop links but nope! Bush had gone NSF

I didn’t have to replace them on my old 07 Panda until 80k when they went wrong

 

[vexorg]

Looks like fiat have more of an issue with bonding the rubber to the arm rather than the quality of rubber.

 

[Pugglt Auld Jock]

I'm more amazed it passed the MOT.

My usual motorfactors has changed to Napa for the suspension parts.

I hate ECP, overpriced and have supplied me the wrong parts a few times. They dont list lemforder either.

Very surprising it passed it's MOT, begs the question as to whether they actually did any real checking? - Easy money if you're just glancing at it and issuing the certificate though. I'm not sure how much the new computerized procedures tie in to the actual physical examination? I think there was an intention to stop this sort of evasion?

My preferred local motor factor was recently taken over by a large motor group - Group Auto I think? - and the shelves are now full of NAPA products. So far a very positive experience from my standpoint. The prices are good and the quality seems fine. I'm well known at this factor and I often chat to counter staff I've known for years, I'm told the NAPA products are produced by the same manufacturers as their previous product brands (which seems logical to me). I feel really pretty confident when I see that NAPA brand on the packaging.

I too have had less than ideal experiences at ECP and I have to say they are a supplier of last resort for me (they're nearest branch is not actually all that near either)

Regarding tightening the mounting bolts. The rear bushes (the ones which failed on yours, and which seem to be a well known fail point on all the small Fiat range so I'm even more surprised the garage didn't catch you on them as your's were very definitely well shot) can be tightened with the suspension uncompressed as the bush doesn't "twist" around it's central metal fitting. The front bolt is best tightened with the suspension somewhere near it's loaded ride height because it does twist and wind up the rubber - think about it. Obviously it would be best to have no "twist" applied to the bushing rubber when the car is stationary with it's weight on all 4 wheels but it's not going to make a great deal of difference if a very small amount of twist is present. It's best to measure the ride height (axle centre to under front wing wheel arch) before you start so then you can compress the front suspension to this height using your jack before tightening the front bolt. I would have the car with it's front up on axle stands to do this job - just as you seem to - and, if I'd forgotten to check the ride height before I started, I'd just put my trolley jack's saddle under the front hub - so applying force to the hub much as would be applied when the wheel is in place - and jack up, so compressing the strut and spring, until the chassis just lifted off the axle stand. The suspension will be somewhere near normal loaded position like this thus allowing the bolt to be tightened with minimal preloading of the bush rubber.

As a final comment. I do all the servicing and a lot of the repairs on all 6 of our extended family's cars and as such I like quite a thorough MOT inspection to be preformed. My local Fiat Indy is strict but fair and I rely on his yearly inspection to act as a backup to the checking I do at service time. If it were me I'd be looking for a new MOT testing station next time. (I'd also stay away from the "lightening fit" type organizations if I were you! as they seem, generally, to be strongly profit motivated?)

 

[Pugglt Auld Jock]

PS. Had a very similar rattle/knocking noise as you with your air intake trunking on the turbo piping in my old diesel Cordoba. Incredibly? it took me almost 2 years of on/off searching and wiggling things about to find it (I owned that car for nearly 20 years) as it was down the back of the battery and wasn't actually the fixing bolt itself but the captive threaded insert which had come just slightly loose from the inner wing. A solid whack with a hammer sorted it though!

 

[Pugglt Auld Jock]

PPS. I think our club hammers may well be related?



Maybe twins? or cousins at least?

 

[vexorg]

I can even remember how or where I got that hammer, probably my most used tool on cars in the last 30+ years of working on them.

I did try jacking the car up to set the suspension height. That didn't work as I had both sides off the ground on axle stands. It wouldn't lift high enough without lifting the whole car off the stand.


I had mixed feelings about the MOT, I do like a stricter MOT as a nice check that all is good with a car. Nice not to need a re-test, but would have like to be told about any issues.

 

[d4zzl3r]

A fun day yesterday of finding all the bolts and nuts to get into the lower arms. It's not that bad a job, though dont think the screws on the wheel liner will last another few years without being blobs of rust. I could probably do it in half the time next time since I know how it goes together now.

Bushes just fell out when they were removed!

Afterwards I took it for wheel alignment, and there was still a noise, more of a vibrating noise of the exhaust or engine part touching the body. Turned out to be this bolt loose that hold the air pipe on the front slam panel. Just seemed to resonate with the engine vibration.

Hi - did you have any trouble getting the support arm out? I've undone everything on the drivers side but i think the washer bottle might need to come out?

 

[vexorg]

Bit annoyed last week, failed MOT on the ball joint of the lower arm on one side.
Only about 12k miles in just under 2 years, I thought it would last longer than that.

Turns out the Napa parts have a 3 year warranty, so at least they agreed that would be changed for free. Waste of an afternoon though.

On the plus side, the rubber bushes were solid and in very good condition.